This is a closer look into Chrysanthos’s eye color changing colors to represent his mood, first mentioned here I think: His eyes changing color, of course, is involuntary, and sometimes doesn’t know they’ve changed color unless someone tells him. Another involuntary action he has is that his fangs grow whenever he is about to take a bite out of something or when he’s angry.  
Here are the color representations:  
Blue: As usual, it means he is either sad, or feeling bummed.  
Light Green: His eyes turn a lighter green then his normal eye color when he is happy, excited, or feeling joyful.  
Pink: This means he either has a crush, or is in love, and when it comes to Glider, it could be either one.mostly the second one  
Red: Of course, red means he’s mad.  
Dark Crimson: When his eyes are this color, it usually means to run away or get pummeled. He’s not mad, and he’s not angry, he is downright pissed and feels rage or betrayal.
 
These are not the only colors though, he still has a lot more.